Equilibria and ammonia

Students mainly experience chemical reactions that appear to go to completion. When they meet a reaction that does not go to completion but which has a reverse reaction occuring they find the concept difficult to understand.

One major misconception students have about equilibrium is that they think equilibrium positions are fixed and once achieved there is no movement of particles between the two 'sides' i.e. they believe that equilibria are static not dynamic.

Le Chateliers Principle is a way of predicting changes to an equilibrium position under some circumstances but is generally wrongly applied due to the misunderstanding about the equilibrium position.

Rate and equilibria are often confused because students think that the rate of one reaction may change while the other slows or remains constant. They have not grasped that rate applies to the system as a whole.

It is important to use a wide range of reversible reactions to help get these ideas across to the students. A variety of simulations and modelling activites are available to support students which are explained in the following list.

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance